My thoughts are that the steel fount Kayen's are from Kopsen. They have the same deep bottom skirt as other lamps from Kopsen and the pump fitted to the ones I have seen are the small diameter flat topped knob version which is also a Kopsen indication. I can see that the pump fitted to yours is of the Nettlefold type (large diameter and dished), but pumps aren't a good indicator. I'll post some pictures of one of mine in a new entry to give some more data.